{ "cells": [ { "cell_type": "markdown", "id": "835c0920-8b71-494a-bf6d-116a53c6bcf5", "metadata": {}, "source": [ "###
San Jose State University
Department of Applied Data Science

**DATA 200
Computational Programming for Data Analytics**

Spring 2024
Instructor: Ron Mak
" ] }, { "cell_type": "markdown", "id": "fa6e822c-4404-40cf-b972-910ece9e64e4", "metadata": {}, "source": [ "# 3.10 Formatted Strings" ] }, { "cell_type": "markdown", "id": "febb0d65-199e-4083-a331-7eb0954bac14", "metadata": {}, "source": [ "#### Use an **f-string** to format a string with embedded values.\n", "#### Inside of an f-string, enclose values to embed in curly braces, such as `{a}`." ] }, { "cell_type": "code", "execution_count": null, "id": "dda43477-f151-4569-a928-c1fbe9ec617b", "metadata": {}, "outputs": [], "source": [] }, { "cell_type": "code", "execution_count": null, "id": "adbeb39d-1dda-4801-b255-e45e5e6018ca", "metadata": {}, "outputs": [], "source": [ "a = 3\n", "b = 4\n", "c = 5\n", "sum = a + b\n", "\n", "str = f'The sum of {a}, {b}, and {c} is {sum}'\n", "str" ] }, { "cell_type": "markdown", "id": "73878ed8-8339-4969-b330-0c7c30e1ff56", "metadata": {}, "source": [ "#### We can use an **f-string** to format our printed output." ] }, { "cell_type": "code", "execution_count": null, "id": "265be183-e88a-4f26-88c2-1a3d3b42e73b", "metadata": {}, "outputs": [], "source": [ "print(f'The sum of {a}, {b}, and {c} is {sum}')\n", "print(f'and their average is {sum/3}')" ] }, { "cell_type": "markdown", "id": "d817ddc5-26a4-4e60-b411-78ec181b1ade", "metadata": {}, "source": [ "#### You can specify how many spaces you want a printed value to take up. However, if a number needs more space, it will take up as many as it needs." ] }, { "cell_type": "code", "execution_count": null, "id": "a7b2a8a6-6f68-4f6c-acc5-65a9223c9f8f", "metadata": {}, "outputs": [], "source": [ "print(f'The sum of {a:5}, {b:5}, and {c:5} is {sum:10}')\n", "print(f'and their average is {sum/3:4}')" ] }, { "cell_type": "markdown", "id": "847d59da-e3c6-4bb0-9993-18870d2d067c", "metadata": {}, "source": [ "## The d and f format specifiers." ] }, { "cell_type": "markdown", "id": "6cef2b81-91b1-4e90-9074-02b9b1b31e4f", "metadata": {}, "source": [ "#### You can end each format specification for an integer value with a `d`. For floating-point numbers such as the average above, you can specify both how many spaces and how many places after the decimal point. End each format specification for a floating-point value with an `f` if you specify the number of decimal places. " ] }, { "cell_type": "code", "execution_count": null, "id": "98a9bf85-0f0d-49d9-8633-44bfa719646a", "metadata": {}, "outputs": [], "source": [ "print(f'The sum of {a:5}, {b:5}, and {c:5d} is {sum:10d}')\n", "print(f'and their average is {sum/3:4.2f}')" ] }, { "cell_type": "markdown", "id": "17cfc062-c56b-4b3e-b5eb-52da904df05c", "metadata": {}, "source": [ "#### When specifying the number of spaces for a value, be sure to include any leading minus sign and, for floating-point values, a space for the decimal point.\n", "- The printed value will be rounded to the number of decimal places you specify. \n", "- If you specify 0 decimal places, the number will print like an integer value, rounded if necessary. \n", "- You can also only specify the number of decimal places, and the printed value will take only as many spaces as it needs." ] }, { "cell_type": "code", "execution_count": null, "id": "8287e660-1912-43f5-8abb-5133d0871246", "metadata": {}, "outputs": [], "source": [ "alpha = -4.6387\n", "\n", "print(f'The value of alpha is {alpha:8.3f}')\n", "print(f'The value of alpha is {alpha:8.0f}')\n", "print(f'The value of alpha is {alpha:.2f}')" ] }, { "cell_type": "markdown", "id": "726a8136-23b9-407f-8703-bc4901ce115e", "metadata": {}, "source": [ "## Automatic labeling with '='\n", "#### This is a great feature to print debugging output." ] }, { "cell_type": "code", "execution_count": null, "id": "a3887b0c-9e4c-485b-a7ba-c4a160e76809", "metadata": {}, "outputs": [], "source": [ "a = 12345\n", "b = 1_234_567_890\n", "c = 123456.987665\n", "\n", "print(f'{a = :6d}')\n", "print(f'{b = :11d}')\n", "print(f'{c = :12.4f}')" ] }, { "cell_type": "markdown", "id": "93204514-02e7-4b89-bfc6-d2630da883a3", "metadata": {}, "source": [ "## Commas in printed numeric values." ] }, { "cell_type": "code", "execution_count": null, "id": "47b8dd60-ad11-4fb9-95a3-3e94379d19a6", "metadata": {}, "outputs": [], "source": [ "a = 12345\n", "\n", "print(f'{a:6,d}')" ] }, { "cell_type": "code", "execution_count": null, "id": "b6795773-4925-44a1-80bf-d942fe85b183", "metadata": {}, "outputs": [], "source": [ "a = 12345\n", "b = 1_234_567_890\n", "c = 123456.987654\n", "\n", "print(f'{a = :6,d}')\n", "print(f'{b = :7,d}')\n", "print(f'{c = :12,.4f}') ## note where the comma goes!" ] }, { "cell_type": "markdown", "id": "6274619a-472c-4030-96ad-7ba14a6a3eb2", "metadata": {}, "source": [ "## Left- and right-justifying and centering" ] }, { "cell_type": "code", "execution_count": null, "id": "eeda0274-bb47-440c-adbc-12d25bc26e6c", "metadata": {}, "outputs": [], "source": [ "print(f'Right-justification is default: |{alpha:10.3f}|')\n", "print(f'Specify right-justification: |{alpha:>10.3f}|')\n", "print(f'Specify left-justification: |{alpha:<10.3f}|')\n", "print(f'Specify centering: |{alpha:^10.3f}|')" ] }, { "cell_type": "code", "execution_count": null, "id": "b3ef455d-485d-4ccc-b85a-08598aef12a8", "metadata": {}, "outputs": [], "source": [ "# (C) Copyright 2024 by Ronald Mak" ] } ], "metadata": { "kernelspec": { "display_name": "Python 3 (ipykernel)", "language": "python", "name": "python3" }, "language_info": { "codemirror_mode": { "name": "ipython", "version": 3 }, "file_extension": ".py", "mimetype": "text/x-python", "name": "python", "nbconvert_exporter": "python", "pygments_lexer": "ipython3", "version": "3.11.5" } }, "nbformat": 4, "nbformat_minor": 5 }